T-Bird authentication problem

When I try sending a message in Thunderbird 3.0, I get this error message: "Sending of message failed.
The SMTP server smtp.comcast.net does not support the selected authentication method. Please change the 'Authentication method' in the 'Account Settings | Outgoing Server (SMTP)'."
Under "authentication method" in my Thunderbird settings are these choices: Normal Password, Encrypted Password, and two others I don't understand. Is this the area the error message is referring to? Normal Password is highlighted. Can someone help me with this? Thanks.

 

If you have ticked 'Use secure authentication' try unticking it, and vice versa (as I don't know whether your ISP uses secure or not)

 

Thanks for your reply. I tried what you suggested and it did not solve the problem.

 

I had problems with Thunderbird. I tied very hard to like it. as it was highly touted.
Fwiw, try Windows Live Mail; it is straight froward, functional and from my point of view, trouble free.
It has been my default email program for some time and has been reliable.
Uninstalling Thunderbird may take some doing.